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CentOS and RHEL 7 have Python 2.7 available in the standard packages. You can install Python 3.6 from source while keeping the current 2.7 install on your machine, so any existing dependencies will not break. You can now run python3.6 Continue reading →

The NES Classic Edition is Nintendo’s miniaturized version of the groundbreaking NES, originally released in 1985. It comes pre-loaded with 30 games and it doesn’t seem like Nintendo provided any means of adding more games to it. Under the hood Continue reading →

A 32 bit version of Raspbian is currently the most common OS that runs on a Raspberry PI. RPI 3 comes equipped with a 64 bit CPU, however at the moment only experimental 64 bit versions of Raspbian may be Continue reading →

Since version 3.2 you can use the $lookup to perform the equivalent of left outer joins in MongoDB. While you should try to design your schema to avoid joins as much as you can, the $lookup nevertheless is a very Continue reading →

On the surface, it seems like the $and operator is useless because it is implicitly applied when MongoDB processes each expression in the query. For instance the following query searches for all products where category=”vehicle” AND brand=”toyota”: However, consider this: Continue reading →

While the MongoDB Aggregation Pipeline can be used to aggregate your data, it is definitely not limited to that and can be used to construct more complicated queries that don’t necessarily do any data aggregation. One of the big advantages Continue reading →

Starting with the MongoDB Java API 3.1 a new GridFS API has been added. It is available under the com.mongodb.client.gridfs package. If you are building a new application then the new GridFS API is the recommended one to use. However Continue reading →

As a general rule, you should try to avoid joining as much as possible in MongoDB. While in traditional relational databases you try to avoid repetition of data and therefore joins are necessary, it is perfectly all right to repeat Continue reading →

Although in Linux you can easily create multi-part zip files, unzipping them can be problematic. By using the -s argument in the zip command you can specify the split size and create split archives. The following example creates split archives Continue reading →

Some time ago, Oracle removed the download links to Oracle 10g Express Edition (XE). If you need to do a new install of the Oracle XE database on your Linux platform, you can download Oracle 11g XE from the Oracle Continue reading →